Thermo-catalytic cracking for conversion of higher hydrocarbons into lower hydrocarbons

ABSTRACT

Described herein are processes and related devices and systems for the conversion of higher hydrocarbons, such as in the form of waste plastics, petroleum sludge, slope oil, vegetable oil, and so forth, into lower hydrocarbons, which can be used as fuels or raw materials for a variety of industrial and domestic uses.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.12/819,137, filed on Jun. 18, 2010, which claims the benefit of U.S.Provisional Application No. 61/218,579, filed on Jun. 19, 2009, thedisclosures of which are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The invention relates generally to the processing of hydrocarbons. Moreparticularly, the invention relates to the conversion of higherhydrocarbons, such as in the form of waste plastics, petroleum sludge,slope oil, vegetable oil, furnace oil, edible oil, rubber products, andso forth, into lower hydrocarbons, which can be used as fuels or rawmaterials for a variety of industrial and domestic uses.

BACKGROUND

Pyrolytic cracking and thermo-catalytic cracking have been used toconvert waste plastics, petroleum sludge, slope oil, and vegetable oilinto lower hydrocarbons. However, many of the processes and devices usedto achieve this conversion have failed to produce useful end productsefficiently and economically to be commercially viable.

Pyrolytic cracking typically refers to a process in which higherhydrocarbons are heated to elevated temperatures of up to about 800° C.at which chemical bonds break to form lower hydrocarbons. To achievethese elevated temperatures, a large amount of energy is involved.Typically, the cost of the energy involved outweighs the value of endproducts produced. Certain existing implementations for pyrolyticcracking use molten metal baths as a heating medium for achievingelevated temperatures. However, achieving these elevated temperaturesusing molten metal baths tends to be inefficient in terms of cost andmaintenance. Moreover, the use of molten metal baths poses occupationalhealth hazards, given the tendency of metals to oxidize over time. Otherexisting implementations carry out a pyrolysis stage, which is thenfollowed by a catalytic conversion stage to convert higher hydrocarbonsinto lower hydrocarbons. However, such implementations continue tosuffer from the use of elevated temperatures and large amounts of energyduring the initial pyrolysis stage.

Thermo-catalytic cracking typically refers to a process of convertinghigher hydrocarbons into lower hydrocarbons in the presence of a set ofcatalysts, such that the process can be carried out at lowertemperatures than those typically involved in pyrolytic cracking. Therehave been a few unsuccessful attempts to incorporate thermo-catalyticcracking in a commercially viable plant that can convert higherhydrocarbons into lower hydrocarbons. There are a number of unresolvedtechnical challenges faced by existing implementations, includinghandling more than one type of feedstock, rendering the processsubstantially continuous, determining a composition of a set ofcatalysts for optimal yield at lower cracking temperatures, delivery offeedstock into a cracking device, removal of residue from the crackingdevice, and tuning the quality and quantity of resulting end products.In addition, thermo-catalytic cracking poses a number of process designchallenges, such as designing a cracking device to achieve optimal heattransfer area, selection of a heating medium, avoiding or reducingunder-utilization of heat transfer area typically encountered in a batchprocessing mode due to depleting level of feedstock, effective removalof residue in the cracking device that can lead to poor heat transfer,and mitigating coke formation on a heat transfer surface of the crackingdevice. These challenges hinder the ability to scale up equipment sizefor commercially viable plants.

It is against this background that a need arose to develop the processfor thermo-catalytic cracking and related devices and systems describedherein.

SUMMARY

Certain aspects of the invention relate to a batch, semi-continuous, orsubstantially continuous process for the conversion of higherhydrocarbons into lower hydrocarbons. In one embodiment, the processincludes: (a) providing a feedstock in the form of higher hydrocarbonsand including at least one solid raw material and at least one liquidraw material and converting the feedstock into a liquid or a semi-liquidphase; (b) bringing a temperature of the feedstock to a prescribedlevel; (c) cracking the feedstock in the presence of a first set ofcatalysts at a temperature lower than a natural pyrolysis temperature ofthe feedstock; (d) evaporating the cracked feedstock into a gaseousphase; (e) restructuring the cracked feedstock in the gaseous phase inthe presence of a second set of catalysts to produce a restructuredgaseous product; (f) condensing the restructured gaseous product toproduce a desired end product; and (g) removing unevaporated anduncracked residues. Other aspects of the invention relate to devices andsystems for carrying out the conversion of higher hydrocarbons intolower hydrocarbons.

In another embodiment, the feedstock includes a mixture of the solid rawmaterial and the liquid raw material.

In another embodiment, the solid raw material includes at least one ofwaste plastics, petroleum sludge, tar sand, used tires, and petroleumresidue, and the liquid raw material includes at least one of used oil,vegetable oil, furnace oil, slope oil, heavy oil, and refinery residualoil.

In another embodiment, cracking the feedstock in (c) is carried outusing a thin-film cracking device.

In another embodiment, the thin-film cracking device creates a thin filmof the feedstock using at least one of wiping, spraying, falling film,rising film, and a roller mechanism.

In another embodiment, the thin-film cracking device includes the firstset of catalysts in a coated form on surfaces that are in contact withthe feedstock.

In another embodiment, the thin-film cracking device is configured toprovide enhanced contact area between the first set of catalysts and thefeedstock and enhanced heat transfer to the feedstock.

In another embodiment, the thin-film cracking device is configured toprovide substantially continuous contact of the first set of catalystswith a heat transfer surface and with a thin film of the feedstock.

In another embodiment, the thin-film cracking device includes amechanism to remove the cracked feedstock in the gaseous phase.

In another embodiment, restructuring the cracked feedstock in (e) iscarried out using a catalytic converter including the second set ofcatalysts.

In another embodiment, the feedstock is pre-conditioned by at least oneof removal of moisture and impurities, washing, dissolving, filtering,breaking, chopping, tearing, crushing, grinding, and pulverizing.

In another embodiment, converting the feedstock into the liquid or thesemi-liquid phase in (a) is carried out using a vessel, and thepre-conditioned feedstock is transferred into the vessel by at least oneof pressure, gravity, vacuum, pump, screw conveyor, and belt.

In another embodiment, the pre-conditioned feedstock in the vessel isconverted into the liquid or the semi-liquid phase by at least one ofheating, dissolving, emulsifying, and breaking.

In another embodiment, the feedstock is purged with an inert gas or amixture of inert gases.

In another embodiment, the feedstock is purged with a material toimprove reactivity of the feedstock.

In another embodiment, undesirable solids, liquids, and gases areremoved from the feedstock by at least one of settling, vaporizing, andcondensing.

In another embodiment, converting the feedstock into the liquid or thesemi-liquid phase in (a) is carried out using a vessel, cracking thefeedstock in (c) is carried out using a thin-film cracking device, andthe feedstock is transferred from the vessel to the thin-film crackingdevice via a temperature controlled heating device.

In another embodiment, cracking the feedstock in (c) is carried outusing a thin-film cracking device, and the first set of catalysts isprovided in the thin-film cracking device by at least one of dosing,injecting, ejecting, providing the first set of catalysts as a liquid, asolid, or a slurry, suspending, retaining, and coating.

In another embodiment, the first set of catalysts is selected fromsilicates, oxides, carbides, hydroxides, carbonates of Na⁺, Ca²⁺, Al³⁺,Fe³⁺, Co²⁺, Ni²⁺, Mn²⁺, Zr⁴⁺, Ti⁴⁺, W⁶⁺, Mg²⁺, V²⁺, Cr³⁺, Sn⁴⁺, Zn²⁺,Ce⁴⁺, Li⁺, K⁺, Mo³⁺, Cu²⁺, Si⁴⁺, Cd²⁺, and Ba²⁺, metals of Ag, Pt, andAu, natural and synthetic zeolites, Fuller's earth, activated charcoal,mixtures of the above, and nanoparticles or powders of the above.

In another embodiment, the feedstock in the thin-film cracking device isheated in the presence of the first set of catalysts to a levelsufficient to crack the feedstock and evaporate the cracked feedstock.

In another embodiment, cracking the feedstock in (c) is carried outusing a thin-film cracking device, and removing unevaporated anduncracked residues in (g) includes transferring the residues in thethin-film cracking device to a bottom of the thin-film cracking device.

In another embodiment, the residues are transferred from the bottom ofthe thin-film cracking device to a residue receiver vessel.

In another embodiment, at least a portion of the residues is transferredfrom the residue receiver vessel to a separate vessel via a temperaturecontrolled device.

In another embodiment, evaporating the cracked feedstock in (d) iscontrolled by a pressure and temperature control device.

In another embodiment, restructuring the cracked feedstock in (e) iscarried out using a catalytic converter including the second set ofcatalysts, and the catalytic convertor is configured for molecularrestructuring of the cracked feedstock.

In another embodiment, cracking the feedstock in (c) is carried outusing a thin-film cracking device, and at least a portion of therestructured gaseous product is transferred back to the thin-filmcracking device.

In another embodiment, the second set of catalysts includes multiplecatalysts that are provided in the catalytic converter.

In another embodiment, the second set of catalysts is provided in thecatalytic converter by at least one of dosing, injecting, ejecting,providing the second set of catalysts as a liquid, a solid, or a slurry,suspending, retaining, and coating.

In another embodiment, the second set of catalysts is selected fromsilicates, oxides, carbides, hydroxides, carbonates of Na⁺, Ca²⁺, Al³⁺,Fe³⁺, Co²⁺, Ni²⁺, Mn²⁺, Zr⁴⁺, Ti⁴⁺, W⁶⁺, Mg²⁺, V²⁺, Cr³⁺, Sn⁴⁺, Zn²⁺,Ce⁴⁺, Li⁺, K⁺, Mo³⁺, Cu²⁺, Si⁴⁺, Cd²⁺, and Ba²⁺, metals of Ag, Pt, andAu, natural and synthetic zeolites, Fuller's earth, activated charcoal,mixtures of the above, and nanoparticles or powders of the above.

In another embodiment, condensing the restructured gaseous product in(f) is carried out using a fractionating column to achieve separation ofthe desired end product by condensation through controlled temperatureand pressure.

In another embodiment, the desired end product includes a set of lowerhydrocarbons in liquid form.

In another embodiment, the desired end product includes a set ofuncondensed gases.

In another embodiment, at least a portion of a condensate is transferredback to the fractionating column for finer separation.

In another embodiment, at least a portion of a condensate is transferredto a storage vessel via a temperature controlled cooling device.

In another embodiment, uncondensed gases are passed through a scrubbingdevice.

In another embodiment, the scrubbed gases are transferred to a storagevessel through controlled temperature and pressure.

In another embodiment, the storage vessel includes a pressure vessel ora tank.

In another embodiment, the storage vessel is maintained at a desiredpressure and a desired temperature by a controller.

In another embodiment, at least a portion of the scrubbed gases istransferred from the storage vessel to a flaring device.

In another embodiment, at least a portion of the scrubbed gases istransferred from the storage vessel to a heating device for use as afuel.

Embodiments of the invention address a number of previously unresolvedtechnical challenges and provide a number of benefits, including:

(1) handling a variety of feedstocks, including mixtures of liquid rawmaterials and solid raw materials, in one process and one system;

(2) performing thermo-catalytic cracking at a lower temperature than anatural pyrolysis temperature of a particular hydrocarbon;

(3) implementing devices and systems to carry out a substantiallycontinuous process that can achieve thermo-catalytic cracking of avariety of feedstocks, including those in mixture form;

(4) implementing devices and systems to carry out a process having ahigher rate of heat transfer and fuller utilization of heat transfersurface, while retaining all three components, namely feedstock, heattransfer surface, and a set of catalysts, in close contact;

(5) efficiently removing undesired impurities and moisture;

(6) pre-conditioning of feedstock for controlled dosing;

(7) improving heat transfer capacity of feedstock;

(8) implementing devices and systems having at least one of thefollowing features:

-   -   controlled and substantially continuous dosing of feedstock into        a cracking device    -   substantially continuous utilization of most, or all, of a heat        transfer surface of the cracking device    -   achieving optimum flow rate or velocity of feedstock over the        heat transfer surface    -   substantially continuous removal of residues from the cracking        device    -   substantially continuous removal of lower hydrocarbon vapors and        off-gases from the cracking device    -   controlled pressure and temperature environment in the cracking        device    -   higher cracking rate achieved in the cracking device    -   structurally reforming cracked hydrocarbons to improve the        quality of a resulting end product    -   providing different catalyst compositions and strengths of        catalysts at different stages of catalytic conversion

Other aspects and embodiments of the invention are also contemplated.The foregoing summary and the following detailed description are notmeant to restrict the invention to any particular embodiment but aremerely meant to describe some embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the nature and objects of some embodimentsof the invention, reference should be made to the following detaileddescription taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic overview of a thermo-catalytic cracking systemincluding four main subsystems denoted by boxes with dashed lines,according to an embodiment of the invention.

FIG. 2 is an enlarged view of subsystem-S1 of FIG. 1, which primarilycarries out operations related to pre-treatment and transportation offeedstock in accordance with an embodiment of the invention.

FIG. 3 is an enlarged view of subsystem-S2 of FIG. 1, which primarilycarries out operations related to dehydration and removal of lowerhydrocarbons from feedstock in accordance with an embodiment of theinvention.

FIG. 4 is an enlarged view of subsystem-S3 of FIG. 1, which primarilycarries out operations related to thermo-catalytic cracking andrestructuring in accordance with an embodiment of the invention.

FIG. 5 is an enlarged view of subsystem-S4 of FIG. 1, which primarilycarries out operations related to fractionation, condensation, andextraction of various categories of fuels in accordance with anembodiment of the invention.

FIG. 6A, FIG. 6B, and FIG. 6C illustrate a thin-film cracking deviceimplemented in accordance with an embodiment of the invention.

FIG. 7 illustrates a gas chromatogram indicating relative proportions ofcarbon chain lengths within a fuel produced in accordance with anembodiment of the invention.

DETAILED DESCRIPTION Definitions

The following definitions apply to some of the aspects described withrespect to some embodiments of the invention. These definitions maylikewise be expanded upon herein.

As used herein, the singular terms “a,” “an,” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to an object can include multiple objects unless thecontext clearly dictates otherwise.

As used herein, the term “set” refers to a collection of one or moreobjects. Thus, for example, a set of objects can include a single objector multiple objects. Objects of a set also can be referred to as membersof the set. Objects of a set can be the same or different. In someinstances, objects of a set can share one or more commoncharacteristics.

As used herein, the term “adjacent” refers to being near or adjoining.Adjacent objects can be spaced apart from one another or can be inactual or direct contact with one another. In some instances, adjacentobjects can be connected to one another or can be formed integrally withone another.

As used herein, relative terms, such as “inner,” “interior,” “outer,”“exterior,” “top,” “bottom,” “front,” “back,” “upper,” “upwardly,”“lower,” “downwardly,” “vertical,” “vertically,” “lateral,” “side,”“laterally,” “above,” and “below,” refer to an orientation of a set ofobjects with respect to one another, such as in accordance with thedrawings, but do not require a particular orientation of those objectsduring manufacturing or use.

As used herein, the terms “connect,” “connected,” and “connection” referto an operational coupling or linking. Connected objects can be directlycoupled to one another or can be indirectly coupled to one another, suchas through another set of objects.

As used herein, the terms “substantially” and “substantial” refer to aconsiderable degree or extent. When used in conjunction with an event orcircumstance, the terms can refer to instances in which the event orcircumstance occurs precisely as well as instances in which the event orcircumstance occurs to a close approximation, such as accounting fortypical tolerance levels or variability of the embodiments describedherein.

As used herein, the term “hydrocarbon” refers to an alkane, an alkene,an alkyne, an arene, or a combination thereof. The term “lowerhydrocarbon” refers to a lower form of an alkane, an alkene, an alkyne,an arene, or a combination thereof, while the term “higher hydrocarbon”refers to a higher form of an alkane, an alkene, an alkyne, an arene, ora combination thereof.

As used herein, the term “alkane” refers to a saturated hydrocarbonmolecule. The term “lower alkane” refers to an alkane that includes from1 to 25 carbon atoms, such as from 8 to 25 carbon atoms, while the term“higher alkane” refers to an alkane that includes more than 25 carbonatoms, such as from 25 to 100 carbon atoms. The term “branched alkane”refers to an alkane that includes a set of branches, while the term“unbranched alkane” refers to an alkane that is straight-chained. Theterm “cycloalkane” refers to an alkane that includes a set of ringstructures, such as a single ring structure or a bicyclo or higher ordercyclic structure. The term “heteroalkane” refers to an alkane that has aset of its carbon atoms replaced by a set of heteroatoms, such as N, Si,S, O, and P. The term “substituted alkane” refers to an alkane that hasa set of its hydrogen atoms replaced by a set of substituent groups,while the term “unsubstituted alkane” refers to an alkane that lackssuch replacement. Combinations of the above terms can be used to referto an alkane having a combination of characteristics. For example, theterm “branched lower alkane” can be used to refer to an alkane thatincludes from 1 to 25 carbon atoms and a set of branches.

As used herein, the term “alkene” refers to an unsaturated hydrocarbonmolecule that includes a set of carbon-carbon double bonds. The term“lower alkene” refers to an alkene that includes from 2 to 25 carbonatoms, such as from 8 to 25 carbon atoms, while the term “higher alkene”refers to an alkene that includes more than 25 carbon atoms, such asfrom 25 to 100 carbon atoms. The term “cycloalkane” refers to an alkenethat includes a set of ring structures, such as a single ring structureor a bicyclo or higher order cyclic structure. The term “heteroalkene”refers to an alkene that has a set of its carbon atoms replaced by a setof heteroatoms, such as N, Si, S, O, and P. The term “substitutedalkene” refers to an alkene that has a set of its hydrogen atomsreplaced by a set of substituent groups, while the term “unsubstitutedalkene” refers to an alkene that lacks such replacement. Combinations ofthe above terms can be used to refer to an alkene having a combinationof characteristics. For example, the term “substituted lower alkene” canbe used to refer to an alkene that includes from 2 to 25 carbon atomsand a set of substituent groups.

As used herein, the term “alkyne” refers to an unsaturated hydrocarbonmolecule that includes a set of carbon-carbon triple bonds. In someinstances, an alkyne can also include a set of carbon-carbon doublebonds. The term “lower alkyne” refers to an alkyne that includes from 2to 25 carbon atoms, such as from 8 to 25 carbon atoms, while the term“higher alkyne” refers to an alkyne that includes more than 25 carbonatoms, such as from 25 to 100 carbon atoms. The term “cycloalkyne”refers to an alkyne that includes a set of ring structures, such as asingle ring structure or a bicyclo or higher order cyclic structure. Theterm “heteroalkyne” refers to an alkyne that has a set of its carbonatoms replaced by a set of heteroatoms, such as N, Si, S, O, and P. Theterm “substituted alkyne” refers to an alkync that has a set of itshydrogen atoms replaced by a set of substituent groups, while the term“unsubstituted alkyne” refers to an alkyne that lacks such replacement.Combinations of the above terms can be used to refer to an alkync havinga combination of characteristics. For example, the term “substitutedlower alkyne” can be used to refer to an alkync that includes from 2 to25 carbon atoms and a set of substituent groups.

As used herein, the term “arene” refers to an aromatic hydrocarbonmolecule. The term “lower arene” refers to an arene that includes from 5to 25 carbon atoms, such as from 8 to 25 carbon atoms, while the term“higher arene” refers to an arene that includes more than 25 carbonatoms, such as from 25 to 100 carbon atoms. The term “monocyclic arene”refers to an arene that includes a single aromatic ring structure, whilethe term “polycyclic arene” refers to an arene that includes more thanone aromatic ring structure, such as two or more aromatic ringstructures that are bonded via a carbon-carbon bond or that are fusedtogether. The term “heteroarene” refers to an arene that has a set ofits carbon atoms replaced by a set of heteroatoms, such as N, Si, S, O,and P. The term “substituted arene” refers to an arene that has a set ofits hydrogen atoms replaced by a set of substituent groups, while theterm “unsubstituted arene” refers to an arene that lacks suchreplacement. Combinations of the above terms can be used to refer to anarene having a combination of characteristics. For example, the term“monocyclic lower arene” can be used to refer to an arene that includesfrom 5 to 25 carbon atoms and a single aromatic ring structure.

Overview of Process for Conversion of Higher Hydrocarbons into LowerHydrocarbons

Described as follows is a process for the conversion of higherhydrocarbons, such as in the form of waste plastics, petroleum sludge,slope oil, vegetable oil, and so forth, into lower hydrocarbons. Thelower hydrocarbons can be produced in the form of liquids, gases,solids, or combinations thereof, and can be used for a variety ofapplications, such as raw materials for industrial applications, fuelsfor industrial and domestic applications, and raw materials forpetroleum-based products. Advantageously, the process can be carried outin a substantially continuous manner for improved efficiency andthroughput, thereby rendering the process suitable for implementation incommercially viable plants. However, it is also contemplated that theprocess can be carried out in a batch manner or a semi-continuousmanner.

In one embodiment, the process is carried out via the followingoperations. It should be recognized that certain of the followingoperations can be omitted, combined, sub-divided, or re-ordered.

In one operation, a feedstock including a set of raw materials isprovided and pre-conditioned to render it suitable for furtherprocessing, such as by removal of moisture and impurities, dissolving,filtering, breaking, chopping, tearing, crushing, grinding, pulverizing,staining, heating or cooling, control of pressure, purging with gases,liquids, or solids, or combinations thereof. The feedstock, eitherbefore or subsequent to pre-conditioning, can include higherhydrocarbons in the form of liquids, a slurry, solid lumps, blocks,sheets, pieces, powders, particulates, flakes, gases, or combinationsthereof. In certain implementations, the feedstock includes at least onesolid raw material and at least one liquid raw material. The solid rawmaterial can include waste plastics, petroleum sludge, tar sand, usedtires, rubber products, petroleum residue, or combinations thereof, andthe liquid raw material can include used oil, vegetable oil, furnaceoil, slope oil, heavy oil, refinery residual oil, synthetic oil, edibleoil, or combinations thereof. Pre-conditioning is carried out to achieveone or more of the following: (a) segregation of moisture andimpurities, such as metals, sand, mud, clay, and wood; (b) decrease inviscosity and improve flowability of the feedstock; (c) improve thermalconductivity of the feedstock; and (d) improve an effective surface areaof the feedstock for improved heat transfer.

In another operation, the pre-conditioned feedstock is conveyed to avessel, which can be referred as a melting vessel or chamber, byapplication of pressure, application of gravity, application of vacuum,pumps, screw conveyors, belts, magnetic devices, vibrating devices,combinations thereof, or any other mechanism for conveyance. Theconveyance of feedstock can be controlled to achieve a desiredthroughput and a desired level of the feedstock in the melting vessel.This can be achieved using a controller, which can be mechanical,electrical, pneumatic, hydraulic, electronic, or combinations thereof.The melting vessel can include a mechanism to achieve stirring, heating,cooling, flashing, atomizing, or combinations thereof. The meltingvessel can also include a mechanism to achieve recirculation ofmaterial, evaporation, condensation, refluxing, or combinations thereof.The melting vessel can have a variety of shapes, such as circular,conical, rectangular, square, cylindrical, annular, tubular, jacketed,or combinations thereof. Stirring in the melting vessel can be achievedby a variety of mechanisms, such as mechanical, electrical, pneumatic,hydraulic, or combinations thereof. The melting vessel can include asingle vessel or multiple vessels that are interconnected or usedindependently.

In another operation, the feedstock is processed in the melting vesselto convert it into a liquid or scmi-liquid phase or to reduce itsviscosity, such as by heating, dissolving, emulsifying, breaking,purging, or combinations thereof. In certain implementations, thefeedstock includes at least one solid raw material and at least oneliquid raw material, and the solid raw material is dissolved or mergedwith the liquid raw material in a heated form, such as at a temperaturein the range of about 150° C. to about 250° C. or about 175° C. to about225° C. and at about atmospheric pressure. Dissolving is carried out toachieve one or more of the following: (a) decrease in viscosity andimprove flowability of the feedstock; (b) improve thermal conductivityof the feedstock; and (c) improve an effective surface area of thefeedstock for improved heat transfer. A resulting solid/liquid mixtureof desired proportions yields a liquid or liquid slurry, which can bekept in circulation and delivered for subsequent processing in acontrolled and substantially continuous manner.

In another operation, the feedstock is purged with nitrogen or anotherinert gas or with a mixture of inert gases to substantially remove andreplace oxygen from the melting vessel. Alternatively, or inconjunction, the feedstock is purged with a suitable material, such as asuitable gas or liquid, to improve reactivity of the feedstock withrespect to subsequent thermo-catalytic cracking. Purging can be achievedby injection, blowing, bubbling, mixing, or combinations thereof.

In another operation, undesirable materials, such as in the form ofsolids, liquids, gases, or combinations thereof, are removed from thefeedstock in a pressure and temperature controlled environment by asuitable mechanism, such as by settling, vaporizing, condensing,filtering, chemical reaction, coalescing, adsorption, or combinationsthereof. The pressure controlled environment can be achieved by, forexample, a blower, a vacuum pump, or combinations thereof, along with acontroller. The temperature controlled environment can be achieved by,for example, a long tube evaporator, a condenser, a radiator, orcombinations thereof, along with a controller.

In another operation, the feedstock is conveyed from the melting vesselto a cracking device, which can be referred as a cracking vessel orchamber, via a temperature controlled heating device. Conveyance to thecracking device can be achieved by, for example, a direct or indirectheat exchanger along with a controller. The feedstock in the form of aliquid or liquid slurry can be kept in circulation in the heat exchangerand delivered to the cracking device in a controlled and substantiallycontinuous manner. This liquid or liquid slurry under circulation isdesirably maintained in a turbulent zone where Reynolds numbers are inthe range of about 5,000 to about 20,000 or about 8,000 to about 15,000for efficient heat transfer and to avoid or reduce hot spots andlocalized charring of hydrocarbon. This turbulent zone can be achievedby measuring a velocity or a flow rate of the feedstock through the heatexchanger and using viscosity and density data tabulated for a varietyof feedstock composition and associated temperature ranges. The flowrate can be measured by, for example, a flow meter, and can becontrolled through speed control of a pump.

In another operation, a set of catalysts is provided in the crackingdevice, such as by dosing into the cracking device or making thecatalysts available in the cracking device by any other mechanism. Forexample, the catalysts can be provided in the cracking device byinjecting, ejecting, providing as a liquid, a solid, or a slurry,suspending or retaining in the cracking device, coating on any surfaceor surfaces of the cracking device, or combinations thereof. Examples ofsuitable catalysts for thermo-catalytic cracking include silicates,oxides, carbides, hydroxides, carbonates of Na⁺, Ca²⁺, Al³⁺, Fe³⁺, Co²⁺,Ni²⁺, Mn²⁺, Zr⁴⁺, Ti⁴⁺, W⁶⁺, Mg²⁺, V²⁺, Cr³⁺, Sn⁴⁺, Zn²⁺, Ce⁴⁺, Li⁺, K⁺,Mo³⁺, Cu²⁺, Si⁴⁺, Cd²⁺, and Ba²⁺, metals of Ag, Pt, Au, and transitionmetals, natural and synthetic zeolites, Fuller's earth, activatedcharcoal, mixtures of the above, and nanoparticles or powders of theabove. For certain implementations, a desirable amount of the catalystscan be in the range of about 0.05% to about 10% by weight or about 0.1%to about 3% by weight, relative to an amount of the feedstock includedin the cracking device. The catalysts can be selected by, for example,selecting a particular combination of the catalysts by weight or byvolume and selecting particular chemical compositions and particularshapes of the catalysts in the form of powder, lumps, granules,globules, nanoparticles, coatings, and so forth. For certainimplementations, a desirable composition and proportion of the catalystsare as follows: about 5-45% by weight of a set of silicates, about 0-45%by weight of a set of zeolites, about 0-15% by weight of a set oftransition metals, about 0-10% by weight of a set of metal carbides,about 0-55% by weight of a set of metal oxides, about 0-15% by weight ofa set of metal hydroxides, and about 0-55% by weight of a set of metalcarbonates.

In another operation, the feedstock is heated in the cracking device andin the presence of the catalysts to a level sufficient to crack thefeedstock and evaporate resulting products. Advantageously, heating canbe carried out at a temperature lower than a natural pyrolysistemperature of the feedstock, such as at a temperature in the range ofabout 275° C. to about 500° C. or about 325° C. to about 425° C. and atabout atmospheric pressure. Heating can involve supplying heat to thecracking device using a heating medium or source, such as molten salt inclose circulation, electrical heating, thermal oil system (or any otherthermal liquid system), steam, flue gases, induction heating, microwave,or combinations thereof, along with a controller.

In another operation, uncracked and unevaporated residues in thecracking device are conveyed to a bottom of the cracking device by, forexample, gravity, wiping, augur, rotary air lock valve, screw conveyor,or combinations thereof. The residues are conveyed from the crackingdevice to a residue receiver vessel, and then conveyed from the residuereceiver vessel to a separate storage vessel via a temperaturecontrolled device, such as by heating or cooling the residues using aheat exchanger, a radiator, or combinations thereof, along with acontroller.

In another operation, cracked and evaporated feedstock is conveyed fromthe cracking device to a catalytic convertor for molecular restructuringinto desired products. Conveyance of the cracked and evaporatedfeedstock to the catalytic convertor can be achieved by, for example,suction through a duct, a pipe, or a tube, pressure, or combinationsthereof, along with a controller. A set of catalysts is provided in thecatalytic converter, such as by dosing into the catalytic converter ormaking the catalysts available in the catalytic converter by any othermechanism. For example, the catalysts can be provided in the catalyticconverter by injecting, ejecting, providing as a liquid, a solid, or aslurry, suspending or retaining in the catalytic converter, coating onany surface or surfaces of the catalytic converter, or combinationsthereof. Examples of suitable catalysts for molecular restructuringinclude silicates, oxides, carbides, hydroxides, carbonates of Na⁺,Ca²⁺, Al³⁺, Fe³⁺, Co²⁺, Ni²⁺, Mn²⁺, Zr⁴⁺, Ti⁴⁺, W⁶⁺, Mg²⁺, V²⁺, Cr³⁺,Sn⁴⁺, Zn²⁺, Ce⁴⁺, Li⁺, K⁺, Mo³⁺, Cu²⁺, Si⁴⁺, Cd²⁺, and Ba²⁺, metals ofAg, Pt, Au, and transition metals, natural and synthetic zeolites,Fuller's earth, activated charcoal, mixtures of the above, andnanoparticles or powders of the above. Any remaining unstructured orheavy hydrocarbons can be transferred back to the cracking device forfurther cracking.

In another operation, a resulting restructured product in a gas form isconveyed from the catalytic converter to a fractionating column toseparate desired end products by condensation through controlledtemperature and pressure. The restructured product in the gas form caninclude hydrocarbon vapors, along with additional vapors of water oradditional liquids and gases. For certain implementations, a portion ofa resulting condensate can be conveyed back to the fractionating columnfor finer separation, such as by refluxing of different condensatesavailable from the fractionating column or any other liquid back to thefractionating column to achieve desired fractions.

In another operation, the condensate is conveyed to a storage vessel orchamber via a temperature controlled cooling device, such as bysub-cooling the condensate to a desired level for transferring andstoring the condensate under safe conditions. Conveyance can be achievedusing, for example, a heat exchanger, a radiator, or combinationsthereof, along with a controller.

In another operation, uncondensed gases, which can include off gases,are passed through a scrubbing device. Resulting scrubbed gases are nextconveyed to a storage vessel or chamber through controlled temperatureand pressure, such as using a pressure regulating valve, a pressurecontrol valve, a rupture disc, or combinations thereof, along with acontroller. The storage vessel can include a pressure vessel or a tank,which is maintained at a desired pressure and a desired temperature bythe controller. Excess gases from the storage vessel can be released toa flaring device. For certain implementations, a desired amount of gasescan be conveyed from the storage vessel to a heating device for use as afuel under controlled conditions, such as in connection with certainoperations described above. Conveyance of the desired amount of gasescan be achieved through controlled temperature and pressure, such asusing a pressure regulating valve, a gas train, a governor, orcombinations thereof, along with a controller.

Devices and Systems for Conversion of Higher Hydrocarbons into LowerHydrocarbons

One of a variety of thermo-catalytic cracking systems for convertinghigher hydrocarbons into lower hydrocarbons is illustrated in FIG. 1through FIG. 5 and is described in the following in accordance with anembodiment of the invention.

Referring first to FIG. 2, liquid hydrocarbon raw materials are storedin a storage tank or container 1, and a horizontal variable speedconveyor moves solid hydrocarbon raw materials from a storage bin orstockpile 3 to a crusher 4. The crusher 4 reduces sizes of over-sizedsolids into a desired size, such as on the order of a few centimeters ora few millimeters. An inclined chain conveyor 5 next conveys thesized-reduced solid materials from the crusher 4 to a hopper 6. Issuesrelated to dust are expected to be minimal, as mechanized conveyors areused instead of pneumatic ones. Also a dust collector associated withthe crusher 4 can further ensure dust-free or dust-reduced operation. Inthe illustrated embodiment, a pump 2 conveys the liquid materials, via aflow control device FCV, from the storage tank 1 to a hold-up vessel 7,which acts as a vapor-liquid separation chamber.

As illustrated in FIG. 2 and FIG. 4, the vessel 7 along with an externaltubular vertical heat exchanger 9 form a long tube recirculationevaporator of the rising film type. A recirculation pump 8 ensures thatthe liquid materials are in substantially constant circulation throughtubes at an appropriate velocity for efficient transfer of heat withlittle or no hot spots. The liquid materials are heated to a temperatureof about 240° C. by hot thermal oil generated by a thermal oil heater 38and circulated by a pump 39 through a shell side of the heat exchanger9. However, the temperature can vary depending on the type of solid andliquid materials, and can be adjusted using a temperature control valveTCV. A primary heat source for the thermal oil heater 38 are off gasesstored in a vessel 29, which is illustrated in FIG. 5, optionallysupplemented by fuel from another source. The off gases, along with anysupplemented fuel, are fired into the thermal oil heater 38 by a burner31B.

The long tube recirculation evaporator creates a hot pool of liquidhydrocarbon, and the solid materials that have undergone size reductionare introduced into the vessel 7, via a flow control device FCV, wherethe solid materials are merged with the hot pool of liquid hydrocarbonand are substantially dissolved therein. This solid/liquid mixture ofdesired proportions yields a liquid or liquid slurry, which can be keptin circulation via the recirculation pump 8 through the heat exchanger 9and the vessel 7. Viscosity of this liquid or liquid slurry ismaintained such that its flow rate or velocity through the heatexchanger 9 is in a turbulent region to enhance heat transfer. Tomaintain the desired viscosity, a temperature and a composition of thisliquid or liquid slurry are automatically adjusted by control devicesTCV. To maintain the desired turbulence in the heat exchanger 9, acapacity of the recirculation pump 8 can be modulated by speed control.Control over proportions of solids/liquids, temperatures, and capacitymodulation of the recirculation pump 8 provides desirablepre-conditioning of the feedstock to initiate thermo-catalytic cracking.

Referring to FIG. 3, an inert gas or a mixture of inert gases from acontainer 44 is conveyed by a pump 45 into the vessel 7 to maintain asubstantially oxygen-free atmosphere in the vessel 7. A rate of pumpingis controlled by a control device (not illustrated). Addition of aninert gas is desirable at or near the beginning of the process to avoidor reduce oxidation. A reactive gas or liquid in a container 46 isconveyed by a pump 47 into the vessel 7 in adequate quantity to promotecracking of different types of hydrocarbons.

Water vapors and vapors of hydrocarbons with carbon chain distributionin the range of C1 to C13 are liberated from the vessel 7, and arecooled in a condenser 10. Gases of lighter fractions shorter than C4 andnon-condensable gases are separated in a reflux drum 11, which isconnected to an incinerator 16, where these gases are flared, bottled,or used as fuel for heaters. Condensed liquid including water andhydrocarbons with carbon chain distribution between C5 and C13 isconveyed by a pump 12 to a vessel 13, where separation occurs throughdifferences in densities. Separated fractions are then conveyed torespective storage tanks 14 and 15.

Referring to FIG. 4, unevaporated liquid, which is at about 240° C. andincludes primarily higher fractions with carbon chain distribution inthe range of C14 to C50 or even higher, passes to a heat exchanger 17and is heated to about 340° C. by hot thermal oil. However, thetemperature can vary depending on the type of hydrocarbons and theirrelative proportions.

A liquid or liquid slurry exiting the heat exchanger 17 is conveyed to acracking device 18 in a controlled and substantially continuous mannerusing a flow control device FCV. The cracking device 18 is designed witha number of advantageous features, including being equipped with arotating device that ensures uniform transfer of pre-heated liquidhydrocarbon onto a heat transfer surface of the cracking device 18. Thedesign of the cracking device 18 allows cracking on a microscopic levelby creating a very thin and substantially continuous film of the liquidor liquid slurry feedstock in intimate contact with a set of catalystsand with the heat transfer surface, such that thermo-catalytic crackingoccurs in the thin film in an efficient manner. For example, the thinfilm of the liquid or liquid slurry feedstock can have a thickness inthe range of about 10 nm to about 5 mm, in the range of about 100 nm toabout 1 mm, or in the range of about 1 μm to about 1 mm. In conjunction,uncracked residues are conveyed to a bottom of the cracking device 18,such that the heat transfer surface is substantially continuouslyrenewed for microscopic level cracking of additional liquid or liquidslurry feedstock that is introduced into the cracking device 18. In suchmanner, the design of the cracking device 18 allows substantiallycontinuous cracking of a mixture of solid and liquid hydrocarbons,without requiring switching of multiple cracking devices or the use ofstandby cracking devices.

One of a variety of implementations for the cracking device 18 isillustrated in FIG. 6A and FIG. 6B and is described in the following inaccordance with an embodiment of the invention.

The cracking device 18 illustrated in FIG. 6A and FIG. 6B is a thin-filmcracking device and includes a jacketed vessel or housing 65, whichhouses a rotating fan-like structure 62 that can be referred as a bladeassembly. The blade assembly 62 is part of a rotor, which also includesa rotor shaft 59, a top disk 60, a set of wiping blades 63, and a flashguard 64. The rotor is driven by a motor 51, which is connected to therotor shaft 59 through a gearbox 52, a coupler 54, and a mechanical seal55. A housing 53 encloses the coupler 54 and the seal 55. A top plate orlid 56 provides top covering for the jacketed vessel 65. In one aspectof the illustrated embodiment, the blade assembly 62 includes anassembly of channel/angle beams in a substantially circular shape withparticular orientation, spacing, and quantity of the beams to yield afan-like structure. One purpose of the blade assembly 62 is to providesuction for vapors formed during catalyst-assisted cracking offeedstock, which occurs on an internal surface of the jacketed vessel 65and in an annular region between the jacketed vessel 65 and the bladeassembly 62. The blade assembly 62 also houses the wiping blades 63 thatare implemented with particular material, size, shape, and number. Thewiping blades 63 can slide freely in a radial direction (relative to anaxis extending between the top and the bottom of the jacketed vessel 65)under centripetal force generated by rotation of the blade assembly 62.During rotation, the wiping blades 63 are forced against the internalsurface of the jacketed vessel 65. In such manner, the wiping blades 63can substantially continuously wipe feedstock droplets splashed on theinternal surface of the jacketed vessel 65. This wiping action of theblades 63 under pressure maintains a thin film of feedstock on theinternal surface of the jacketed vessel 65.

Still referring to FIG. 6A and FIG. 6B, a molten or liquefied feedstockis delivered into the jacketed vessel 65 through a set of nozzles 58.This liquid or semi-liquid feedstock falls on the top disk 60, which hasa side wall with V-shaped notches. The feedstock is delivered onto theinternal surface of the jacketed vessel 65 through a spilling orsplashing mechanism through these V-shaped notches under centripetalforce. A variety of other designs can be used in place of, or inconjunction with, these V-shaped notches, such as slots, slits, holes,and so forth. Once deposited on the internal surface of the jacketedvessel 65, the feedstock is substantially continuously wiped in agenerally upward direction by the wiping blades 63. Variousimplementations for the wiping blades 63 are illustrated in FIG. 6C inaccordance with an embodiment of the invention. As can be appreciated,the wiping blades 63 have generally upward directed grooves that canspread the feedstock generally upwards against gravity, such as atangles in the range of about 0 to about 90 degrees, about 5 to about 50degrees, about 10 to about 45 degrees, or other positive angularorientations relative to a horizontal plane. It should be recognizedthat the implementations illustrated in FIG. 6C are provided by way ofexample, and a variety of other implementations are contemplated.

Referring back to FIG. 6A and FIG. 6B, a residence time and a reactiontime of the feedstock in the jacketed vessel 65 can be controlled by avariety of factors, such as rotor speed, dosing rate of the feedstock,design of grooves, design of the blade assembly 62, and so forth. Theflash guard 64 inhibits or prevents any solid residue formed duringcatalyst-assisted cracking, such as carbon particles formed on theinternal surface of the jacketed vessel 65, from contaminating aresulting cracked vapor phase, which is conveyed into an annular regionof the rotor. This vapor rises through a set of vapor outlets 61 andthen through a nozzle 57. A solid or semi-solid residue formed duringcracking falls to a bottom plate of the jacketed vessel 65, which has aninclination angle to allow the residue to flow to one end of thejacketed vessel 65. Once at that end, the residue is conveyed by asuitable mechanism, such as a screw conveyer, to remove the residue on asubstantially continuous basis. As illustrated in FIG. 6A, the jacketedvessel 65 also includes a dish-shaped end at its bottom, which providesan annular region below the inclined bottom plate, and includes anadditional heating medium to maintain the residue at a desiredtemperature for conveyance.

Turning back to FIG. 4, a set of catalysts is provided or made availableto the cracking device 18 by substantially continuous dosing, such asvia a pump. Dosing can be achieved in a controlled matter by a flowcontrol device. There is also a provision for coating of inner surfacesof the cracking device 18 by a desired set of catalysts. For certainimplementations, either, or both, of the heat transfer surface and therotating device (or a spraying, falling film, rising film, roller, orany other mechanism used to create a thin film as well as conveyuncracked residues towards the bottom) can be coated with a set ofcatalysts. In another aspect of the design of the cracking device 18, aset of catalysts can be made available throughout a transition from aliquid or liquid slurry to various cracked fractions of hydrocarbons,and a composition and relative proportions of the catalysts can vary atdifferent locations within the cracking device 18, depending upon acomposition of cracked hydrocarbons at a particular location, therebyachieving higher cracking yields. For example, a composition andrelative proportions of the catalysts can vary from top to bottom, witha higher dosing or amounts of certain ones of the catalysts at thebottom relative to the top.

The cracking device 18 is maintained under a nitrogen (or any otherinert gas) blanketing so as to substantially exclude oxygen and otheratmospheric gases. The cracking device 18 is thus substantially purgedof oxidizing gases and is pressure-controlled. To achievethermo-catalytic cracking, the cracking device 18 is heated to a rangeof about 400° C. to about 420° C. by a molten salt heating medium, whichcan include an eutectic mixture of water soluble inorganic salts ofpotassium nitrate, potassium nitrite, and sodium nitrate. The heatingmedium is provided from a heater 40 and circulated by a pump 41 in aclosed circuit. A primary heat source for the heater 40 are off gasesstored in the vessel 29, which is illustrated in FIG. 5, optionallysupplemented by fuel from another source. The off gases, along with anysupplemented fuel, are fired into the heater 40 by a burner 31A. A dumptank 42 is included for storage of molten salt, and is heated with aheating coil using thermal oil from the thermal oil heater 38 at thetime of initial start-up and at the time of shut-down. A pump 43 conveysthe molten salt to the heater 40 at start-up.

Cracked hydrocarbons in a gaseous form are conveyed for molecularrestructuring as further described below. Residues and contaminants,which are substantially continuously removed from the heat transfersurface of the cracking device 18, are recovered in the form of asemi-solid or slurry from the bottom of the cracking device 18. Theseresidues are cooled in a heat exchanger 32, conveyed to a receiver 35,and then conveyed by a pump 36 to a container 37. Alternatively, or inconjunction, these residues are conveyed via a screw conveyor 33 to areceiver 34.

The catalysts used in the cracking device 18 typically assist incracking of carbon chains longer than C25, and a resulting crackedmaterial passes to a catalytic converter or reformer 19, which ismaintained at a desired temperature by a temperature control valve and acontroller. The catalytic converter 19 includes a set of catalysts toreform short carbon chains, such as those shorter than C6. By operatingin conjunction, the cracking device 18 and the catalytic converter 19can produce a fuel composition with a carbon chain spanning C8 to C25. Amajority of resulting hydrocarbon molecules can include sixteen carbonatoms per molecule, and can satisfy the criteria of commerciallyacceptable fuel, such as commercially acceptable diesel fuel.

Referring next to FIG. 5, vapors exiting the catalytic converter 19 areconveyed to a fractionating column 20, where the following four streamsof end products are separated: (1) Gaseous stream of non-reformedfractions or off gases, with carbon chain distribution in the range ofC1 to C4 (hydrocarbons with carbon chain distribution in the range of C5to C7 can be included in this stream, another stream described below, oras a separate stream); (2) Fuel with carbon chain distribution in therange of C8 to C13, conforming generally to gasoline (petrol) orkerosene; (3) Fuel with carbon chain distribution in the range of C14 toC20 and peaking at about C16, conforming generally to diesel; and (4)Heavy fuel with carbon chain distribution in the range of C20 to C25.

Off gases exiting a top of the fractionating column 20 are cooled by aheat exchanger 25, and are conveyed through a scrubber 26, where thegases are scrubbed with an alkaline solution or a caustic solution andcirculated by a pump 27. The cooled and scrubbed gases are next conveyedby a pump 28 and stored in a reservoir 29. A pressure control valve PCVregulates a pressure of the reservoir 29, and excess gases are releasedto a flaring device 30. The reservoir 29 also serves as a fuel sourcefor the burners 31A and 31B, which were previously described withreference to FIG. 4.

Referring to FIG. 5, the other fuel streams are condensed in respectivecondensers 21A, 21B, and 21C, and are then conveyed to respective refluxvessels 22A, 22B, and 22C. A portion of a condensate in each stream isrefluxed back to the fractionating column 20, while remainingdistillates (overhead products) are conveyed to storage tanks 24A, 24B,and 24C, assisted by pumps 23A, 23B, and 23C. Although the fractionatingcolumn 20 is illustrated as producing four streams or fractions, more orless streams can be collected and stored depending upon the particularapplication.

Laboratory analysis indicates that resulting fuels are consistent withthe criteria for commercially acceptable fuel, such as in terms ofcarbon chain distribution with a peak occurrence of C16 molecules. Aflash point of the fuels can be in the range of about 18° C. to about60° C., and blends of the fuels can yield various industrial fuels withdesirable flash points.

In some instances, characteristics of resulting fuels can be dependentupon types of raw materials used, as the raw materials can vary in theirmolecular structures. In one instance, a mixture of 10% by weight ofwaste oil, 40% by weight of high density polyethylene (HDPE), and 40% byweight of low density polyethylene (LDPE) yielded a resulting productwith the results of Table 1 that are expressed in % by weight(approximate). FIG. 7 illustrates a gas chromatogram of the resultingproduct.

TABLE 1 Non-condensable gases 5 Fraction C8 to C13 5 Diesel C14-C20 78Fraction C20-C25 7 Residue 5

While the invention has been described with reference to the specificembodiments thereof, it should be understood by those skilled in the artthat various changes may be made and equivalents may be substitutedwithout departing from the true spirit and scope of the invention asdefined by the appended claims. In addition, many modifications may bemade to adapt a particular situation, material, composition of matter,method, or process to the objective, spirit and scope of the invention.All such modifications are intended to be within the scope of the claimsappended hereto. In particular, while the methods disclosed herein havebeen described with reference to particular operations performed in aparticular order, it will be understood that these operations may becombined, sub-divided, or re-ordered to form an equivalent methodwithout departing from the teachings of the invention. Accordingly,unless specifically indicated herein, the order and grouping of theoperations are not limitations of the invention.

What is claimed is:
 1. A cracking device for converting higherhydrocarbons into lower hydrocarbons, comprising: a jacketed vesselincluding a top, a bottom, and an internal surface; a blade assemblyhoused in the jacketed vessel and including wiping blades adjacent tothe internal surface of the jacketed vessel; and a motor connected tothe blade assembly and configured to rotate the blade assembly, whereinthe jacketed vessel is configured to receive a feedstock adjacent to thetop of the jacketed vessel, and, upon rotation of the blade assembly,the wiping blades are configured to spread the feedstock to create afilm of the feedstock adjacent to the internal surface of the jacketedvessel; wherein the jacketed vessel further includes a coating adjacentto the internal surface of the jacketed vessel, and the coating includesa set of catalysts to promote cracking of the feedstock.
 2. The crackingdevice of claim 1, wherein, upon rotation of the blade assembly, thewiping blades are configured to slide in a radial direction towards theinternal surface of the jacketed vessel.
 3. The cracking device of claim1, wherein the jacketed vessel is configured such that cracked feedstockis removed adjacent to the top of the jacketed vessel, and uncrackedresidues are removed adjacent to the bottom of the jacketed vessel.
 4. Acracking device for converting higher hydrocarbons into lowerhydrocarbons, comprising: a jacketed vessel including a top, a bottom,and an internal surface; a blade assembly housed in the jacketed vesseland including wiping blades adjacent to the internal surface of thejacketed vessel; and a motor connected to the blade assembly andconfigured to rotate the blade assembly, wherein the jacketed vessel isconfigured to receive a feedstock adjacent to the top of the jacketedvessel, and, upon rotation of the blade assembly, the wiping blades areconfigured to spread the feedstock to create a film of the feedstockadjacent to the internal surface of the jacketed vessel; wherein, uponrotation of the blade assembly, the wiping blades are configured tospread the feedstock in a generally upward direction.
 5. The crackingdevice of claim 4, wherein at least one of the wiping blades includes agroove having a positive angular orientation relative to a horizontalplane.
 6. A cracking device, comprising: an interior chamber including acatalyst; an exterior jacket encompassing the interior chamber; a heatsupply positioned between the exterior jacket and the interior chamber,the heat supply configured to heat a surface of the interior chamber; ablade assembly; an intake configured to receive a waste material in theform of a liquid or a liquid slurry, wherein the cracking device isconfigured to allow for a relative movement between the interior chamberand the blade assembly and thereby wipe the received waste materialalong a portion of the surface of the interior chamber; and a vaporoutlet configured to convey gases out of the cracking device following acracking of the received waste material through the wiping of thereceived waste material along the portion of the surface of the interiorchamber in the presence of the catalyst; wherein the blade assembly isconfigured such that the relative movement between the interior chamberand the blade assembly moves the received waste material in a directionof at least partial opposition to gravity, thereby increasing aresidence time of the wiped received waste material along the portion ofthe surface of the interior chamber.
 7. The cracking device of claim 6,wherein the heat supply is a heating medium.
 8. The cracking device ofclaim 6, wherein the heat supply is a heating source.
 9. The crackingdevice of claim 6, wherein the heat supply heats the surface of theinterior chamber such that the received waste material is heated to atemperature within the range of 325° C. to 425° C.
 10. The crackingdevice of claim 6, the blade assembly comprising a plurality of blades,wherein at least one of the plurality of blades is configured to slideradially towards the surface of the interior chamber.
 11. The crackingdevice of claim 6, wherein the interior chamber is pressure controlled.12. The cracking device of claim 6, wherein the blade assembly isconfigured such that the relative movement between the interior chamberand the blade assembly conveys, aided by gravity, a cracking residue toa portion of the cracking device at a lower elevation than an elevationof the intake.
 13. A cracking device, comprising: an interior chamberincluding a catalyst; an exterior jacket encompassing the interiorchamber; a heat supply positioned between the exterior jacket and theinterior chamber, the heat supply configured to heat a surface of theinterior chamber; a blade assembly; an intake configured to receive awaste material in the form of a liquid or a liquid slurry, wherein thecracking device is configured to allow for a relative movement betweenthe interior chamber and the blade assembly and thereby wipe thereceived waste material along a portion of the surface of the interiorchamber; and a vapor outlet configured to convey gases out of thecracking device following a cracking of the received waste materialthrough the wiping of the received waste material along the portion ofthe surface of the interior chamber in the presence of the catalyst; theblade assembly comprising at least one blade, wherein the catalyst iscoated on at least one of the at least one blade and the portion of thesurface of the interior chamber.